During a live-stream presentation, developer Yosuke Hayashi confirmed that Fire Emblem Warriors has gone gold. The game's development is officially over when it comes to the Japanese release. Now they'll spend time polishing the game, squashing some bugs, and more.

Yeah, and that's called a feature freeze, which is put in place when the game is feature complete. Gone gold mean the game is ready to be printed, 100% finished. No more (hopefully) bugs.
Sorry if I sounds pedantic, but I was a bit confused by the title, as it is way too soon for it to go gold...